The present invention relates to optical fiber ribbons and, more particularly, to the spacing between optical fibers of optical fiber ribbons.
Optical fiber is a very popular medium for large bandwidth applications, and as a result there is a demand for increased numbers of optical fibers. In response to these demands, optical fiber ribbons have been developed. An optical fiber ribbon includes a planar array of optical fibers that extend longitudinally and are laterally adjacent, and the optical fibers are bonded together as a unit.
It is conventional for adjacent optical fibers of an optical fiber ribbon to be in an abutting side-by-side arrangement. As a result, the spacing between adjacent optical fibers in an optical fiber ribbon is often less than the spacing between adjacent optical receptacles of optical devices that optically communicate with the optical fiber ribbon. Optical devices that optically communicate with an optical fiber ribbon include optical input or output devices, which respectively introduce optical signals into or receive optical signals from the optical fibers of optical fiber ribbon. It is common to prepare an optical fiber ribbon for attachment to the optical receptacles of an optical input or optical output device by striping the bonding material of the optical fiber ribbon away from one end of the optical fiber ribbon. A sufficient amount of the bonding material is stripped away so that exposed ends of the optical fibers can be manually spaced apart from one another and be respectively received by the receptacles of the target optical device.
Often it is necessary for relatively long lengths of optical fibers to be exposed at the end of an optical fiber ribbon to obtain the spacing necessary to connect to the relatively far spaced apart receptacles of the target optical device. The binding material that holds the optical fibers of an optical fiber ribbon together provides some protection to the optical fibers; therefore, the optical fibers that are exposed by the stripping are at a relatively greater risk of being damaged. In addition, long lengths of loose optical fibers that extend from an optical fiber ribbon are at risk of becoming tangled and disorganized, and can be difficult to manually manage. These risks or disadvantages are becoming greater and greater as optical fibers and associated equipment become more densely packaged in response to the increasing demand for optical fibers.
The present invention provides methods and apparatus for manufacturing optical fiber ribbons and, more specifically, for manufacturing multipitch optical fiber ribbons.
In accordance with one aspect of the present invention, an assembly for fabricating an optical fiber ribbon from optical fibers that extend in a longitudinal direction is provided. The assembly includes a spacing device having spacing guides that are spaced apart from one another in a lateral direction that is generally perpendicular to the longitudinal direction. Each spacing guide is operative for respectively receiving and guiding an optical fiber of the optical fibers. The spacing device is operative to vary the spacing between the spacing guides in the lateral direction. The assembly may further include a moving device for advancing the optical fibers generally in the longitudinal direction through their respective spacing guides so that the spacing of the spacing guides is imparted upon portions of the optical fibers that are downstream from the spacing guides. The assembly may further include a bonding device positioned downstream from the spacing guides and operative for applying bonding material to the portions of the optical fibers that are downstream from the spacing guides. The bonding material bonds the portions of the optical fibers that are downstream from the spacing guides together to form an optical fiber ribbon.
In accordance with one aspect of the present invention, the spacing guide includes a wall that extends generally arcuately about an axis that extends generally in the lateral direction. The wall further extends generally in the lateral direction and includes an outer surface that generally extends generally arcuately about the axis and in the lateral direction. The wall defines grooves that are open at the outer surface and extend generally arcuately about the axis, and portions of the grooves function as the spacing guides. The grooves are spaced apart from one another in the lateral direction, and the spacing between the grooves varies with respect to an arcuate direction that is defined about the axis. Those grooves are relatively narrow grooves that originate from a relatively wide groove that is also open at the outer surface and extends generally arcuately about the axis. The narrow grooves diverge Is they extend generally in the arcuate direction away from the wide groove.
In accordance with another aspect of the present invention, the assembly for fabricating an optical fiber ribbon includes a frame, and the spacing guide is pivotally connected to the frame for pivoting about the axis. The fabricating assembly optionally includes a cross member that is movably mounted to the frame and can be positioned in close proximity to the outer surface of the spacing guide. The cross member can extend generally in the lateral direction across the grooves so that the cross member cooperates with the grooves to define spacing apertures that respectively receive the optical fibers. The spacing guide can include marks that can be aligned with the cross member to define intervals along the grooves in the arcuate direction.
In accordance with another aspect of the present invention, a method of manufacturing an optical fiber ribbon is provided. In accordance with one example of the method, the optical fibers are advanced along diverging travel paths defined by the grooves of the spacing guide. As the optical fibers are advanced the optical fibers become further spaced apart from one another in the lateral direction. In accordance with one example, the advancing of the optical fiber ribbons along the travel paths is facilitated by moving the spacing guide relative to the optical fibers. More specifically, the advancing of the optical fiber ribbons is facilitated by rotating the spacing guide about an axis. The increased spacing between the optical fibers is maintained by bonding the optical fibers together. The increased spacing between the optical fibers can be established over a long length of the optical fibers by establishing translational movement between the optical fibers and the spacing guide.
In accordance with another aspect of the present invention, binding material is removed from an optical fiber ribbon to expose portions of the optical fibers of the optical fiber ribbon. The exposed portions of the optical fibers are advanced along the diverging travel paths and are thereafter bonded together to provide a multipitch optical fiber ribbon. As one example, the multipitch optical fiber ribbon includes optical fibers that extend longitudinally and are laterally adjacent. The optical fibers are bonded together by bonding material having opposite first and second ends. A lateral first spacing is defined between adjacent optical fibers at the first end of the bonding material, a lateral second spacing is defined between adjacent optical fibers at the second end of the bonding material, and the first spacing is different from the second spacing.